Abstract: The rotor drive assembly is utilized in driving a rotor assembly in an apparatus for centrifugal liquid processing of whole blood wherein whole blood is withdrawn from a donor, passed into a bowl held by the rotor assembly and the blood is centrifuged to separate the same into at least three components within the bowl. One component which is to be collected is withdrawn at a fixed rate of volumetric displacement while the other two components are withdrawn at variable rates of volumetric displacement. The other two components are recombined and returned to the donor. The withdrawal of the one component is optically monitored to determine whether or not either one of the other components is being mixed with the one component. The rotor drive assembly includes a unitary vertical drive shaft having a lower rotatable collar, an intermediate fixed collar and an upper rotatable collar mounted thereon.

Abstract: The support arm is used in an apparatus for the centrifugal liquid processing of whole blood wherein whole blood is withdrawn from a donor and passed through a flexible tubing of a fluid system of the apparatus into a bowl thereof where the blood is centrifuged to separate the same into at least three components. One component which is to be collected is withdrawn through a flexible tubing at a fixed rate of volumetric displacement while the other two components are withdrawn through flexible tubings at variable rates of volumetric displacement. The other two components are recombined and returned to the donor. The withdrawal of the one component is optically monitored to determine whether or not either one of the other components is being mixed with the one component. The support arm is positioned above the bowl for guiding the tubings to the bowl in a first position and is pivotal horizontally to a second position where the bowl can be easily removed.